Drawing board for steel rule dies



June 18, 1963 F. J- COHARA 3,093,906

DRAWING BOARD FOR STEEL RULE DIES Filed April 1, 1960 44 f am V NVENTOR.344M arm. BY.

ATT'Y,

United States This invention relates to the making and manufacture ofsteel rule dies and is more particularly concerned with a drawing boardof special design particularly adaptable for use by the draftsrnan inthe preparation of steel rule dies.

Otherwise stated, the invention contemplates the provision of a drawingboard adaptable for use in the manufacture of steel rule dies and havingmeans whereby the workpiece may be easily and securely held in positionfor accurate and precise work thereon.

More specifically stated, it is a principal object and accomplishment ofthe invention to provide means whereby the workpiece may be removed fromthe drawing board for other work thereon and then be capable of beingreplaced in its previous position on the drawing board in precisely thesame former position for further work.

It is an important object and accomplishment of the invention to providea steel rule die drawing board which is simple to operateand rugged andreliable in use.

Another important object and accomplishment of the invention is toprovide a steel rule die drawing board having adjustable means providingversatility in use and whereby said drawing board may conveniently andquickly accommodate various sized workpieces.

An ancillary object and accomplishment of the invention is to provide anew and novel drawing board for use in the manufacture of steel ruledies and consideration being given to the design and selection ofmaterials in the manufacture thereof to prevent warping and distortionof the base of the drawing board as well as the marginal working edgesso that extremely accurate and precise work may be continuouslyperformed on any workpiece placed on the drafting board.

The invention seeks, as a final object and accomplishmeat, to provide asteel rule die drawing board of the character indicated and which isparticularly characterized by a design arrangement to moreadvantageously and satisfactorily perform the functions required of itand adapted to provide a compact unit which will successfully combinethe factors of structural simplicity and durability, and yetbeeconomical to manufacture.

Additional objects, features and advantages of the invention disclosedherein will be apparent to persons skilled in the art after theconstruction and operation are understood from the within description.

It is preferred to accomplish the various objects of this invention andto practice the same in substantially the manner as hereinafter morefully described, and as more particularly pointed out in the appendedclaims.

Embodiments of the invention are illustrated in the accompanying drawingforming a part hereof and wherein:

FIG. 1 is a perspective view of the steel rule die drawing boardillustrating a workpiece disposed thereon and a T-square in its normaloperating position at one edge of said drawing board;

FIG. 2 is a top view of an adjustable pressure controlled workpieceholding device with portions thereof shown in section to more clearlyillustrate the construc tion; and

FIG: 3 is a sectional view of a portion of the drawing board for steelrule dies, this view being taken substantially on the plane of the line3-3 on FIG. 1.

The drawing is to be understood to be more or less of a schematiccharacter for the purpose of illustrating atent and disclosing a typicalor preferred form of the improvements contemplated herein and in thedrawings like reference characters identify the same parts in theseveral views. 7

Referring to the drawings, particularly to FIG. 1, the drawing board forsteel rule dies contemplated by the present invention is designated inits entirety by the numeral 20 and comprises a base 21 of asubstantially rectangular shape and preferably made of canvasimpregnated Bakelite, marginal straight edges respectively indicated at22 and 23 formed of brass and attached to the base 21 at two marginaledges as shown in FIG. 1 but having a Masonite filler 24 disposedbetween the base 21 and the straight edges 22 and 23, said base 21having a plurality of through apertures 25 adapted to adjustably andreleasably receive securing pins 26 and 27 respectively forming a partof pressure controlled locking devices indicated in their entireties bythe numerals 30 and 31 and which are adaptable for locating andmaintaining a workpiece A in its proper position with respect to thedrawing board 20, and a straight edge T- squa-re indicated in itsentirety by the numeral 33.

Attention is now invited to FIGS. 1 and 3 wherein it can be seen thatthe base 21 is provided with equally spaced through apertures as at 25and each aperture at the top regions thereof is provided with acountersunk opening 36 in order to act as a guide and more easilyreceive stud portions of the securing pins 26 and 27. It is veryimportant in a drawing board of the type contemplated herein that therebe a minimum of wanping because of the extreme accuracy required whenworking on the workpiece A and in order to facilitate the drawing ofabsolute parallel lines and lines at right angles to same. It has beenfound preferable to form the base of canvas impregnated Bakelite becausethis material is not generally affected by temperature, moisture,humidity, etc., and will maintain its shape under normal circumstancesin use and may be cut to precise dimensions for use in a drawing boardas contemplated by this invention. As may best be seenin FIGS. 1 and 3,two marginal edges are provided withthe straight edges 22 and 23preferably formed of brass and secured to the base 21 as shown. Each ofthe straight edges 22 and 23 are provided with a plurality of apertures40 each having screw thread portions disposed therein adapted to receivescrew thread portions *41 of a brass stud 42 and any projections thatmay appear are filed smooth as at 43 so that the top surface of thestraight edges 22 and 23 are smooth and free from obstructions. Thelower end projections 44 of the stud 42 are adapted for receipt into anaperture 45 in the base 21, said aperture 45 at the lower regionsthereof being provided with an enlarged opening 46 adapted toaccommodate the lock washer 47 and nut 48 as shown.

In FIG. 3 it can be seen that the Masonite filler 24 is disposed betweenthe respective straight edges 2-2 and 23 and the base 21, and saidMasonite filler 24 is provided with a suitable aperture as at 50 toaccommodate portions of the screw thread stud 41.

It is important to note that the apertures 45 and 50 are slightly largerthan the diameter of the screw thread stud 41 in order to provideadjustment of the marginal straight edges 22 and 23 with respect to thebase 21.

Particular attention i directed to the recess 54 which is provided inorder to assure accuracy of the marginal straight edges 22 and 23 and sothat no portions of the workpiece A would be in contact with theMasonite filler 24 when disposed on the drawing board. Otherwise stated,the surface 55 of the brass marginal straight edges 22' and 23 arerelied upon to maintain the workpiece 1.9 in its proper location on thedrawing board 21. The relatively small recess 54 may also be used toaccommodate any small particles of Waste materials coming from;erasures, etc., while working on the workpiece A.

Particular attention is invited to FIG. 1 wherein the pressurecontrolled locking devices 30 and 31 are shown in one of many relativelocations on the base 21 and in FIG. 2 there is shown a detail plan viewof one of the pressure controlled locking devices. Because each of thesepressure controlled locking devices is of identical construction it isonly necessary to describe one and the locking device as indicated bythe numeral 31 will be described herein.

In FIG. 2 the pressure controlled locking device 31 comprises abodyportion 60 having curved end regions 61 and a flat side 62 in opposedrelation to the curved end portions 61. The body 60 is provided with arecessed studs 65 and 66 of the pressure controlled locking devices 30and 31 so that the workpiece A is held securely in the drawing board 20.It can be seen that various sized workpieces may be employed andappropriate adjustrnents can be made as hereinbefore described in orderto accommodate these ditterent sized workpieces.

If the draftsman requires removal of the workpiece A from the drawingboard 20 for other Work thereon or for any other purpose, it is onlynecessary for him to exert appropriate manual pressure upon theworkpiece A sutlicient to overcome the pressures exerted upon the twoedges of the workpiece A by the pressure responsive studs '65 and 66 andthereafter conveniently remove same channel 63 having a plurality ofthrough apertures 64 vdisposed therein and adaptable to accommodate thesecuring pin 27. Five through apertures as at 64 are shown in order toprovide a measure of adjustment in the use of the pressure controlledlocking devices to securely but adjustably hold the workpiece A in itsrelafrom the drawing board 20. Replacement of the workpiece A in itsoriginal position on the drawing board 20 can be accomplished by placingthe workpiece A so that the appropriate edges will be in contact withthe pressure responsive studs 65 and 66 of both pressure controlledlocking devices and 31 and by exerting appropriate manual pressure theworkpiece A can be moved into' position so that the other two edges willsnap into contact with the marginal straight edges 22 and 23 there? bypermitting the draftsman to replace the workpiece A on the drawing board20 in substantially its original position thereon.

From the foregoing disclosure it may be observed that I have provided animproved drawing board for use in the manufacture of steel rule dies andwhich efliciently ture 69in the body 60 of the pressure controlledlocking device 31. "In order to facilitate longitudinal movement of thestud v65 within the aperture 69 there is provided a Bakelite sleevebearing 70: which is suitably fixedly secured in the position as shownby cementing or any other similar process. means urging the stud 65 toits projecting position as shown in FIG. 2 there is provided a spring7-1, one end 72 of which is adapted for engagement with the innermostregions of the aperture 69' and the other end 73 of which is arrangedfor engagement with enlarged head portions 68 of the stud 65.

In reviewing the relative disposition .of the pressure controlledlockingdevices ,30 and 31 in FIG. 1 it can In order to provide a pressure beseen that the outer end portions of the studs 65 and 66are in engagementwith the side portions of the workpiece A and by proper selection of anaperture 25 in the base 21 and an aperture 64 in the pressure controlledlocking device '31 the securing pin 27 may be passed therethrough so asto provide locking pressure in the studs 65 and 66 to maintain theworkpiece A in its relative position with respect to the base 21. Thus,it can be seen that the pressure controlled locking device 31 willprovide such locking presure to adjacent side edges of the workpiece Awhile the pressure controlled locking device 30 will provide a similardegree of pressure to another adjacent side of the workpiece A, therebyto maintain the other two sides of the workpiece A in proper engagementwith the respective marginal straight edges 22 and 23 all as shown inFIG. 1. a

The pressure controlled locking device 30 and 31 are 7 preferably madeof Bakelite but any suitable plasticmaterial may also be used ifdesired. The T-square 33 may be of conventional design and need not befurther described herein.

In operation the user will select a workpiece as at A and dispose it onthe base 21 of the drawing board 20 as shown in FIG. 1 and then byjudicious selection of the appropriate apertures 25 in the base 21 andaperture 64 in the pressure controlled locking devices 30 and 31 andthereafter insert respectively the securing pins 26 and 27 so thatappropriate pressure is applied to the two edges of the workpiece A bythe pressure responsive fulfills the objects thereof as hereinbeforestated and which provides numerous advantages which may be summarized asfollows: a

(l) Structurally simple, eflicient and durable;

(2) Economical to manufacture and readily adaptable to mass productionmanufacturing principles; and

(3) The provision of a drawing board for steel rule dies and havingmeans whereby the workpiece may be not only easily and securely held inposition for accurate and precise work thereon but also permitting thesame workpiece to be readily removed for other work thereon and beconveniently and quickly replaced precisely in its p former position forfurther work.

While I have illustrated preferred embodiments of my invention, manymodifications may be made without departing from the spirit of theinvention, and I do not wish to be limited to the precise details ofconstruction set forth, but wish to avail myself of all changes withinthe scope of the appended claims.

I-claim:

1. A drawing board for steel rule dies comprising two straight edgesdisposedat right angles to each other and adjustably mounted on aperforated base adapted to accommodate a four-sided workpiece so thattwo sides of said workpiece are in contact with said straight edges,securing means respectively manually operable to mount the straightedgesto said perforated base in adjustable position with respect to saidperforated base, said base having a plurality of equally spacedapertures, pressure responsive locking means for holding a work piece'inposition on said drawing board, said pressure responsive locking meansbeing movable and adjustably secured to said base, a stud pin forming apart of said pressure responsive locking means and operable for manuallymovably and adjustably securing said pressure responsive means to saidbase and having portions thereof adapted to be received into one of saidequally spaced apertures in said base, said pressure responsive locking'means comprising a body having curved end regions and a flat side inopposed relation to the curved end regions, said body having a recessedchannel having a plurality of through apertures disposed therein andadaptable to accommodate said stud pin, a pair of studs disposed inspaced relationship and with portions thereof projecting from the flatside of said body and axially movable in relation to said bodyresponsive to manual l l l pressure, separate spring means disposedwithin said body and in engagement with a respective stud to provide aresilient force urging 51 id studs axially outwardly of said body sothat end portions thereof are in engagement with a side of saidworkpiece to exert resilient pressure thereon to maintain an opposedside of said workpiece in contact with an adjacent straight edge, andeach of said studs having means respectively cooperating with portionsof said body to limit the axial outward movement of said studs withrespect to said body.

2. In a drawing board for steel rule dies including a base adapted toaccommodate a workpiece and provided with a plurality of equally spacedapertures and having straight edges adjustably mounted on at least twomarginal sides thereof at right angles to each other; pressureresponsive locking means for holding a workpiece in position on saiddrawing board, said pressure responsive locking means being manuallymovable and adjustably secured to said base by a stud pin forming a partof said pressure responsive locking means and said stud pin havingportions thereof adapted to be received in one of said equally spacedapertures in said base, said pressure responsive locking meanscomprising a body having curved end regions and a flat side in opposedrelation to the curved end regions, said body having a recessed channelhaving a plurality of through apertures disposed therein and adaptableto accommodate said stud pin, a pair of studs disposed in spacedrelationship and with portions thereof projecting from the fiat side ofsaid body and axially movable in relation to said body responsive tomanual pressure, separate spring means disposed within said body and inengagement with a respective stud'to provide a resilient force urgingsaid studs axially outwardly of said body so that end portions thereofare in engagement with a side of said workpiece to exert resilientpressure thereon to maintain an opposed side of said work-piece incontact with an adjacent straight edge, and each of said studs havingmeans respectively cooperating with portions of said body to limit theaxial outward movement of said studs with respect to said body.

3. In a drawing board for steel rule dies, the combination with a baseof substantially rectangular shape and adapted to accommodate aworkpiece, said base having a plurality of equally spaced apertures, ofmarginal straight edges adjustably mounted on at least two marginalsides of said base in a manner to provide at least two straight edges atright angles to each other, and pressure responsive locking meansmanually movable and adjustably secured to said base by a stud pinforming a part of said pressure responsive locking means and said studpin having portions thereof adapted to be received into one of saidequally spaced apertures in said base, said pressure responsive lockingmeans comprising a body having curved end portions and a flat side inopposed relation to the curved end portions, said body having a recessedchannel having a plurality of through apertures disposed therein andadaptable to accommodate said stud pin, a pair of studs disposed inspaced relationship and with portions thereof projecting from the flatside of said body and axially movable in relation to said bodyresponsive to manual pressure, separate spring means disposed withinsaid body and in engagement with a respective stud to provide aresilient force urging said studs axially outwardly of said body so thatend portions thereof are in engagement with a side of said workpiece toexert resilient pressure thereon to maintain an opposed side of saidworkpiece in contact with an adjacent straight edge, and each of saidstuds having means respectively cooperating with portions of said bodyto limit the axial outward movement of said studs with respect to saidbody.

4. A drawing board for steel rule dies comprising, a base ofsubstantially rectangular shape and adapted to accommodate a workpiece,said base having a plurality of equally spaced apertures, straight edgesadjustably mounted on at least two marginal sides of said. base andproviding two straight edges at right angles to each other, a firstpressure responsive locking device for holding a workpiece in positionon said drawing board, a stud pin forming part of said first pressureresponsive locking device and having portions adapted to be receivedinto one of said equally spaced apertures in said base, said firstpressure responsive locking device being manually movable and adjustablysecured to said base and having pressure responsive means adapted forengagement with a side of said workpiece to exert resilient pressurethereon to maintain an opposed side of said workpiece in contact with anadjacent straight edge, said first pressure responsive locking devicecomprising a body having curved end regions and a flat side in opposedrelation to the curved end regions, said body having a recessed channelhaving a plurality of through apertures disposed therein and adaptableto accommodate said stud pin, a pair of studs disposed in spacedrelationship and with portions thereof projecting from the fiat side ofsaid body and axially movable in relation to said body responsive tomanual pressure, separate spring means disposed within said body and inengagement with a respective stud to provide a resilient force urgingsaid studs axially outwardly of said body so that end portions thereofare in engagement with a side of said workpiece to exert resilientpressure thereon to maintain an opposed side of said workpiece incontact with an adjacent straight edge, and each of said studs havingmeans respectively cooperating with portions of said body to limit: theaxial outward movement of said studs with respect to said body, and asecond pressure responsive locking device of identical construction tosaid first pressure responsive locking device but arranged so that theaxially movable studs forming a part thereof are in engagement withanother side of said workpiece to exert resilient pressure thereon tomaintain another opposed side of said workpiece in contact with theother adjacent straight edge.

References Cited in the file of this patent UNITED STATES PATENTS165,888 Stevenson July 20, 1875 724,116 Maley Mar. 31, 1903 744,559Kendrick Nov. 17, 1903 1,499,989 Lehmann July 1, 1924 1,807,895 CheshireJune 2, 1931 2,002,348 Louviaux May 21, 1935 2,097,209 Cooper et al Oct,26, 1937 2,470,437 Hoert-h May 17, 1949 FOREIGN PATENTS 898,673 FranceJuly 10, 1944

1. A DRAWING BOARD FOR STEEL RULE DIES COMPRISING TWO STRAIGHT EDGESDISPOSED AT RIGHT ANGLES TO EACH OTHER AND ADJUSTABLY MOUNTED ON APERFORATED BASE ADAPTED TO ACCOMMODATE A FOUR-SIDED WORKPIECE SO THATTWO SIDES OF SAID WORK-P;IECE ARE IN CONTACT WITH SAID STRAIGHT EDGES,SECURING MEANS RESPECTIVELY MANUALLY OPERABLE TO MOUNT THE STRAIGHTEDGES TO SAID PERFORATED BASE IN ADJUSTABLE POSITION WITH RESPECT TOSAID PERFORATED BASE, SAID BASE HAVING A PLURALITY OF EQUALLY SPACEDAPERTURES, PRESSURE RESPONSIVE LOCKING MEANS FOR HOLDING A WORKPIECE INPOSITION ON SAID DRAWING BOARD, SAID PRESSURE RESPONSIVE LOCKING MEANSBEING MOVABLE AND ADJUSTABLY SECURED TO SAID BASE, A STUD PIN FORMING APART OF SAID PRESSURE RESPONSIVE LOCKING MEANS AND OPERABLE FOR MANUALLYMOVABLY AND ADJUSTABLY SECURING SAID PRESSURE RESPSONSIVE MEANS TO SAIDBASE AND HAVING PORTIONS THEREOF ADAPTED TO BE RECEIVED INTO ONE OF SAIDEQUALLY SPACED APERTURES IN SAID BASE, SAID PRESSURE RESPONSIVE LOCKINGMEANS COMPRISING A BODY HAVING CURVED END REGIONS AND A FLAT SIDE INOPPOSED RELATION TO THE CURVED END REGIONS, SAID BODY HAVING A RECESSEDCHANNEL HAVING A PLURALITY OF THROUGH APERTURES DISPOSED THEREIN ANDADAPTABLE TO ACCOMMODATE ASAID STUD PIN, A PAIR OF STUDS DISPOSED INSPACED RELATIONSHIP AND WITH PORTIONS THEREOF PROJECTING FROM THE FLATSIDE OF SAID BODY AND AXIALLY MOVABLE IN RELATION TO SAID BODYRESPONSIVE TO MANUAL PRESSURE, SEPARATE SPRING MEANS DISPOSED WITHINSAID BOLDY AND IN ENGAGEMENT WITH A RESPECTIVE STUD TO PROVIDE ARESILIENT FORCE URGING SAID STUDS AXIALLY OUTWARDLY OF SAID BODY SO THATEND PORTIONS THEREOF ARE IN ENGAGEMENT WITH A SIDE OF SAID WORKPIECE TOEXERT RESILIENT PRESSURE THEREON TO MAINTAIN AN OPPOSED SIDE OF SAIDWORKPIECE IN CONTACT WITH AN ADJACENT STRAIGHT EDGE, AND EACH OF SAIDSTUDS HAVING MEANS RESPECTIVELY COOPERATING WITH PORTIONS OF SAID BODYTO LIMIT THE AXIAL OUTWARD MOVEMENT OF SAID STUDS WITH RESPECT TO SAIDBODY.